RU2558762C2 - 2,3,4,5-tetraalkylmagnesacyclonone-2,4-dienes synthesis method - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a method for the synthesis of 2,3,4,5-tetraalkylmagnesacyclonone-2,4-dienes of formula

.

The method implies a chemical reaction between 2,3,4,5-tetraalkylmagnesacyclopenta-2,4-dienes and ethylene with Cp₂ZrCl₂ used as a catalyst. The reaction proceeds with ethylene pressure of 2.0-2.5 MPa and 2,3,4,5-tetraalkylmagnesacyclopenta-2,4-diene:Cp₂ZrCl₂ molar ratio of 10:(0.3-0.6), in the mixture of diethyl ether and THF with the volume-to-volume ratio of 5:1, at the temperature of ~20°C for 10-12 hours.

EFFECT: invention relates to the compounds, which may be used in the synthesis of bifunctional and heterocyclic compounds, or within catalyst systems in oligomerisation and polymerisation reactions of olefins, diene and acetylene hydrocarbons.

1 tbl, 1 ex

Description

The present invention relates to methods for producing new organomagnesium compounds (MOS), in particular, to a method for producing 2,3,4,5-tetraalkylmagnesacyclonon-2,4-dienes of the general formula (1):

where R = C ₂ H ₅ , n-C ₃ H ₇ , n-C ₄ H ₉

These compounds can be used in the synthesis of bifunctional and heterocyclic compounds, as well as components of catalytic systems in the processes of oligo- and polymerization of olefin, diene and acetylene hydrocarbons.

A known method for producing 2,3,4,5-tetraalkylmagnazacyclopenta-2,4-dienes (2) [RF Patent No. 2290406 (2006)] by the reaction of disubstituted acetylenes with n-BuMgCl in the presence of Cp ₂ ZrCl ₂ zirconacenedichloride taken in a molar ratio R -≡-R: n-BuMgCl: Cp ₂ ZrCl ₂ = 10: (20-26) :( 1.0-1.4). The reaction is carried out in an argon atmosphere at room temperature (~ 20 ° C) and atmospheric pressure. The reaction time of 10-14 hours, the yield of target products 45-60%. The reaction is carried out in diethyl ether and proceeds according to the scheme:

R = C ₂ H ₅ , n-C ₃ H ₇ , n-C ₄ H ₉

The known method does not allow to obtain 2,3,4,5-tetraalkylmagnesacyclonone-2,4-dienes (1).

The known method [K.F. Fujita, Y. Ohnuma, N. Yasuda, N. Tani. Magnesium-butadiene Addition Compounds Isolation, Structural Analysis and Chemical Reactivity // J. Organomet. Chem., 201 (1976) 113] for the preparation of unsaturated organomagnesium compounds, namely magnesacyclonon-3,7-diene of the general formula (3). The reaction of butadiene with metal magnesium in the presence of catalytic amounts of methyl iodide at a temperature of 40 ° C in tetrahydrofuran for 48 hours with a yield of 69% according to the scheme:

In a known manner, 2,3,4,5-tetraalkylmagnesacyclonone-2,4-dienes cannot be obtained (1).

Thus, in the literature there is no information on the synthesis of 2,3,4,5-tetraalkylmagnesacyclonon-2,4-dienes (1).

A new method is proposed for producing 2,3,4,5-tetraalkylmagnesacyclonone-2,4-dienes (1).

The essence of the method consists in the interaction of 2,3,4,5-tetraalkyl-substituted magnesacyclopent-2,4-dienes (2) and ethylene in the presence of a catalyst of zirconacenedichloride Cp ₂ ZrCl ₂ . The ratio (2): Cp ₂ ZrCl ₂ = 10: (0.3-0.6). In the reaction zone, the excess pressure of ethylene is maintained in the range of 2.0-2.5 MPa. The reaction is carried out at room temperature (~ 20 ° C). The reaction time is 10-12 hours. As a solvent, it is necessary to use a mixture of diethyl ether and tetrahydrofuran in a volume ratio of Et ₂ O: THF = 5: 1, in other solvents the yield of the target products (1) is negligible. The yield of target products (1) 60-80%.

The reaction proceeds according to the scheme:

where R = C ₂ H ₅ , n-C ₃ H ₇ , n-C ₄ H ₉ ; [Zr] = Cp ₂ ZrCl ₂

The target products (1) are formed only with the participation in the reaction of tetrasubstituted magnesacyclopenta-2,4-dienes (2), ethylene, and a catalyst of zirconacene dichloride Cp ₂ ZrCl ₂ . In the presence of other catalysts based on transition metal complexes (e.g., Ni (acac) ₂ , Fe (acac) ₃ , Cp ₂ TiCl ₂ , Pd (acac) ₂ , CuCl, Ti (OBu) ₄ ), the target products (1) are not formed .

The reaction in the presence of a catalyst Cp ₂ ZrCl ₂ more than 6 mol.% In relation to (2) does not lead to a significant increase in the target products (1). The use of a Cp ₂ ZrCl ₂ catalyst in the reaction of less than 3 mol% reduces the yield of MOC (1).

The experiments were carried out at room temperature ~ 20 ° C. At higher temperatures (for example, 50-60 ° C), the yield (1) decreases, and at low temperatures (for example, 0 ° C), the reaction rate decreases.

Changing the ethylene pressure upwards leads to the formation of larger cyclic MOS, and a decrease in pressure below 2.0 MPa reduces the yield of the target products (1).

Significant differences of the proposed method.

1. In the proposed method, the starting compounds are 2,3,4,5-tetraalkyl-substituted magnesacyclopenta-2,4-dienes (2), ethylene, and a catalyst Cp ₂ ZrCl ₂ . In the known method, cyclic unsaturated MOC (3) is obtained using butadiene, magnesium metal and catalytic amounts of CH ₃ J.

The proposed method has the following advantages.

1. The method allows to obtain in high yield 2,3,4,5-tetraalkylmagnesacyclonone-2,4-dienes (1), the synthesis of which is not described in the literature.

The method is illustrated by the following examples.

EXAMPLE 1. In a 100 ml stainless steel autoclave in an argon atmosphere, 50 mmol of previously obtained 2,3,4,5-tetrapropylmagnazacyclopent-2,4-diene (2) (1.0 M solution in Et ₂ O), 10 are placed ml of dry THF, at a temperature of 0 ° C, 1.5 mmol of a Cp ₂ ZrCl ₂ catalyst is added to this mixture, the temperature is brought to room temperature and the autoclave is sealed. Ethylene is pumped into the autoclave through a special device. The excess pressure of ethylene in the reaction zone is maintained at 2.0 MPa until the completion of the reaction. The reaction mixture was stirred at room temperature for 10 hours. Get individual 2,3,4,5-tetrapropylmagnesacyclonone-2,4-diene (1). The yield of the target product was determined by hydrolysis products. Hydrolysis of MOS (1) produces 5,6,7-tripropylundeca-4,6-diene (4) with a yield of 60%, and during deuterolysis, respectively, 1,8-dideutero-1,2,3,4-tetrapropyl octa-1, 3-diene (5).

Spectral characteristics of the products of hydrolysis and deuterolysis: 5,6,7-Tripropylundeca-4,6-diene (4): T. boil. 226 ° C (30 mmHg). IR spectrum (v, cm ^-1 ): 3080, 2950, 2900, 2850, 1640, 1450, 1370, 910, 895, 720. ¹ H NMR spectrum (δ, ppm): 0.82-1.05 m (15H , CH ₃ ), 1.32-1.47 m (12H, CH ₂ ), 1.95-2.21 m (10H, C = CH ₂ ), 5.24-7.1 m (1H, = CH). ¹³ C NMR spectrum (δ, ppm): 13.57, 13.77, 13.89, 14.12, 14.55 (C ¹ , C ¹¹ , C ¹⁴ , C ¹⁷ , C ²⁰ ), 23.58 (C ² ), 32.33 (C ³ ) , 126.71 (С ⁴ ), 149.51 (С ⁵ ), 139.48 (С ⁶ ), 139.42 (С ⁷ ), 32.54 (С ⁸ ), 29.75 (С ⁹ ), 22.73 (С ¹⁰ ), 40.18 (С ¹² ), 23.59 (C ¹³ ), 33.24 (C ¹⁵ ), 22.48 (C ¹⁶ ), 34.75 (C ¹⁸ ), 21.73 (C ¹⁹ ). [M] ⁺ 278.

1,8-Dideutero-1,2,3,4-tetrapropyllocta-1,3-Dien (5): T. boiling 227 ° C (30 mmHg). IR spectrum (ν, cm ^-1 ): 3080, 2950, 2900, 2850, 2170 (CD), 1640, 1450, 1375, 910, 895, 720. ¹ H NMR spectrum (δ, ppm): 0.81 -1.04 m (14Н, СН ₃ , CH ₂ D), 1.31-1.48 m (12Н, СН ₂ ), 1.93-2.22 m (10Н, С = СН2). ¹³ C NMR spectrum (δ, ppm): 131.00 (C ¹ , t, J _CD = 19 Hz), 13.57, 13.77, 13.89, 14.12 (C ¹¹ , C ¹⁴ , C ¹⁷ , C ²⁰ ), 148.62 ( C ² ), 137.36 (C ³ ), 138.91 (C ⁴ ), 30.69 (C ⁵ ), 29.58 (C ⁶ ), 23.11 (C ⁷ ), 13.59 (C ⁸ , t, J _CD = 19 Hz), 28.59 ( C ⁹ ), 23.21 (C ¹⁰ ), 40.17 (C ¹² ), 21.95 (C ¹³ ), 32.91 (C ¹⁵ ), 22.48 (C ¹⁶ ), 34.39 (C ¹⁸ ), 21.52 (C ¹⁹ ). [M] ⁺ 280.

Other examples confirming the method are shown in table 1.

All experiments were carried out at room temperature (~ 20 ° C).

Claims (1)

The method of obtaining 2,3,4,5-tetraalkylmagnesacyclonone-2,4-dienes of the formula (1):

characterized in that the interaction of 2,3,4,5-tetraalkylmagnazacyclopent-2,4-dienes with ethylene in the presence of a catalyst - zirconacene dichloride Cp ₂ ZrCl _{2 is} carried out under an excess ethylene pressure of 2.0-2.5 MPa, with a molar ratio of 2,3,4 5-tetraalkylmagnesacyclopenta-2,4-diene: Cp ₂ ZrCl ₂ = 10: (0.3-0.6), in a solvent mixture diethyl ether-THF, taken in a volume ratio of 5: 1, at a temperature of ~ 20 ° C within 10-12 hours.